Another thing that would be cool but I doubt they'd do since we've seen no sign of it is if certain characters either played off each other or reduced one another's cost in some way. For example, General Crespin lead an A-wing wing. He isn't a unique squadron pilot but he could be a crew officer who reduced the cost of A-wings -2 or something. General Salm lead a Y-wing wing so he could do the same or add +1 speed to them. Or it could continue like Tallon's where you exhaust a card so that it is active but limited. Just spitballing.

In the generic sense, Mon Calamari Crew could reduce the cost of all MCs (eventually) and deploy for free to MCs. Or Mouse Droids could add +1 to engineering for Imperials (since they, uh, improve networking...).

If the characters affect other ships, like Salm and Y-wings above, if his ship is destroyed then the Y-wings lose their buff. It would really create the sense of key individuals coordinating the battle.

I'm sure crew that affect the stats of ships they're one are possible, although in many cases they may be modifications intstead, like the Expanded Hangars. FFG has to be careful not to give too many abilities to multiple cards that can go in different slots, lest you end up being able to double your ship's Squadron value with Expanded Hangars, Flight Controllers, Gara Petothel, etc.

I'm equally certain that there won't be cards that reduce the point values of ships or squadrons, since they would be impossible to balance. Either you're not running enough A-Wings to justify Crespin's cost and you never play him, or you are, and he's a must play, because he would be cheaper than free.